Martin Lesueur, Thomas Poulet, Emmanouil Veveakis

Permeability is a critical parameter for geological resources characterisation. Its evolution with respect to porosity is particularly interesting and many research initiatives focus on deriving such relationships, to understand some hydraulic impacts of microstructure alteration. Permeability evolution from chemical reactions for instance can become complex as flow channels may open during rock dissolution. In this contribution, we show that this phenomenon can lead to irregular porosity-permeability curves and permeability hysteresis after reprecipitation. Current approaches describing permeability as a simple function of porosity can therefore not capture this behaviour and we advocate instead the use of dynamic modelling for such scenarios. We demonstrate our approach by modelling a dissolution/precipitation cycle for a unit cell pore channel and quantify the process at larger scale on three different rock samples, whose microstructures are reconstructed from segmented micro-Computerised Tomography scans.